“I've always been an arrogant SOB with overblown ideas of what I can and can't do,” said Stewart Copeland, whose attributes clearly do not include a gift for understatement.

Best known as the drummer and founder of the Anglo-American rock trio The Police, with which he played a sold-out reunion show here last summer at Cricket Wireless Amphitheatre, Copeland is also an accomplished composer.

He earned a Golden Globe nomination for his first film score, 1983's “Rumble Fish.” He went on to write the music for 14 feature films, six video games and a similar number of TV series and TV films. His credits include an opera, “Holy Blood and Crescent Moon,” which was commissioned by the Cleveland Opera and debuted in 1989, and a score for the San Francisco Ballet's 1986 production of “King Lear.”

Copeland returns to San Diego for three appearances today and tomorrow as part of the 40th anniversary season of the La Jolla Music Society's SummerFest.

Tonight at Sherwood Auditorium he will attend a “bonus concert prelude” screening of his 2006 film documentary, the home movie-ish “Everybody Stares: The Police Inside Out.” Copeland will do a Q&A session with the audience afterward and touch upon the rise, fall and rise again of The Police, which was formed in London in 1977, imploded in 1984, then reunited for a hugely lucrative world tour in 2007 and 2008.

Tomorrow night's concert at Sherwood will feature the world premiere of Copeland's “Retail Therapy” (which he wrote mostly in hotel rooms during the Police reunion), along with performances of his 2008 piece “Celeste” and two of his earlier compositions, “Gene Pool (1994) and “Kaya” (1998). He is scheduled to perform on percussion on all four of his works, although Copeland stressed that — unlike the other musicians on stage with him — he will not be reading his parts from his score.

“I'm playing from memory,” Copeland said. “I know the pieces and the meaning and purpose of the rhythms. So, instead of reading it, I can come up with something that will work on the night — and that goes for pretty much all my performances. In fact, the drummer is often in conflict with the composer.”

Since he will be fulfilling both roles, who will likely emerge victorious — Copeland the drummer, or Copeland the composer?

“It depends,” he said. “On the night, the drummer. On the cutting-room floor of the studio, the composer. If it's a recording, I can cut that drum bastard to pieces.”

He grew more serious as he discussed how unusual it is now to find classical musicians who can improvise with the skill and ease of the best jazz and rock artists.

“There are very few who can read the page and improvise off of what they see,” he lamented. “Somehow, there's a disconnect between what the eye analyzes on the page and turning it into a performance. Musicians who can do both are rare; I'm not even sure I'm one.”

This admission was the only time Copeland expressed even a hint of self-doubt during an extended interview.

Brash and arrogant, funny and thoughtful, he has been a rock star for more than 30 of his 57 years. But he refuses to be bound by pop-music conventions, as befits an outspoken maverick who admits to sending fan letters about his own drumming to various publications back in his pre-Police days in England.

Copeland's first high-profile composing assignment came in 1983, when he wrote the “Rumble Fish” score for film director Francis Ford Coppola.

“I hadn't seen a page of written music since I was in college in San Diego in 1973 and studied with Dr. Mary K. Phillips at downtown's School of Performing Arts,” said Copeland, who was then enrolled here at USIU and credits Phillips as a pivotal early mentor.

“I wrote the ‘Rumble Fish’ score by hand and had to remember what whole notes and quarter notes were. I'd always written musical figures on mallet instruments, but for strings you needed long notes, or ‘footballs’ as we call them in the trade.”

Yet, while he takes his work seriously, no matter what the genre, he makes no pretenses about being a “serious” musician.

“I'm using instruments normally associated with classical music, Copeland said. “But I don't write classical music — I live in the 21st century.”

And, it transpires, back in the first century as well.

At the time of this interview, he was in Dusseldorf, Germany, completing his orchestral score for “Ben Hur Live,” a multimillion-dollar stage production that opens in London next month. It features a cast of 400, along with five chariots, two galleons and 175 animals.

“It's the whole movie, performed on stage, and I'm writing a two-hour monstrosity,” said Copeland, who studies orchestration with a professor at UCLA.

“The movie had a seminal score (by multiple Oscar-winner Miklos Rozsa). But like Jimi Hendrix's use of the wah-wah pedal, it was copied by so many others that it's hard to appreciate how revolutionary it was. Musically, I have a blank canvas.

“The script is in Arabic, Latin and Roman. For the English markets the tour visits, they talked me into being the narrator. The actors' dialogue is pretty brief — ‘Masala, you (expletive)!’ ‘Judas, kiss my (expletive)!’ Then the narrator comes in, and says: ‘They disagreed.’ ”

Copeland is the first Rock and Roll Hall of Fame inductee to earn a commission from SummerFest, which is seeking to feature more film composers. But he doubts his star power will matter much in a venue as small as Sherwood Auditorium.

“How much clout do you need to sell 490 tickets?” he quipped.

“There have always been rock 'n' roll dabblers in the classical world and there have always been classical players who wish they were rock stars, but I don't think it's a trend that's gaining momentum. At various times, opera companies and orchestras say: ‘Look at all those kids going to rock concerts. How do we get some into our theater? Let's get a rock star!’

“The critics generally don't go for it. Because an underlying dynamic, which applies to every niche of art, is that you pay your dues. You work your way up, prove yourself and learn from the masters. But then some (expletive) out of left field comes out on stage, and the critics say: ‘This just isn't right.’